1 #include "erfa.h"
2
eraPnm06a(double date1,double date2,double rnpb[3][3])3 void eraPnm06a(double date1, double date2, double rnpb[3][3])
4 /*
5 ** - - - - - - - - - -
6 ** e r a P n m 0 6 a
7 ** - - - - - - - - - -
8 **
9 ** Form the matrix of precession-nutation for a given date (including
10 ** frame bias), IAU 2006 precession and IAU 2000A nutation models.
11 **
12 ** Given:
13 ** date1,date2 double TT as a 2-part Julian Date (Note 1)
14 **
15 ** Returned:
16 ** rnpb double[3][3] bias-precession-nutation matrix (Note 2)
17 **
18 ** Notes:
19 **
20 ** 1) The TT date date1+date2 is a Julian Date, apportioned in any
21 ** convenient way between the two arguments. For example,
22 ** JD(TT)=2450123.7 could be expressed in any of these ways,
23 ** among others:
24 **
25 ** date1 date2
26 **
27 ** 2450123.7 0.0 (JD method)
28 ** 2451545.0 -1421.3 (J2000 method)
29 ** 2400000.5 50123.2 (MJD method)
30 ** 2450123.5 0.2 (date & time method)
31 **
32 ** The JD method is the most natural and convenient to use in
33 ** cases where the loss of several decimal digits of resolution
34 ** is acceptable. The J2000 method is best matched to the way
35 ** the argument is handled internally and will deliver the
36 ** optimum resolution. The MJD method and the date & time methods
37 ** are both good compromises between resolution and convenience.
38 **
39 ** 2) The matrix operates in the sense V(date) = rnpb * V(GCRS), where
40 ** the p-vector V(date) is with respect to the true equatorial triad
41 ** of date date1+date2 and the p-vector V(GCRS) is with respect to
42 ** the Geocentric Celestial Reference System (IAU, 2000).
43 **
44 ** Called:
45 ** eraPfw06 bias-precession F-W angles, IAU 2006
46 ** eraNut06a nutation, IAU 2006/2000A
47 ** eraFw2m F-W angles to r-matrix
48 **
49 ** Reference:
50 **
51 ** Capitaine, N. & Wallace, P.T., 2006, Astron.Astrophys. 450, 855.
52 **
53 ** Copyright (C) 2013-2014, NumFOCUS Foundation.
54 ** Derived, with permission, from the SOFA library. See notes at end of file.
55 */
56 {
57 double gamb, phib, psib, epsa, dp, de;
58
59
60 /* Fukushima-Williams angles for frame bias and precession. */
61 eraPfw06(date1, date2, &gamb, &phib, &psib, &epsa);
62
63 /* Nutation components. */
64 eraNut06a(date1, date2, &dp, &de);
65
66 /* Equinox based nutation x precession x bias matrix. */
67 eraFw2m(gamb, phib, psib + dp, epsa + de, rnpb);
68
69 return;
70
71 }
72 /*----------------------------------------------------------------------
73 **
74 **
75 ** Copyright (C) 2013-2014, NumFOCUS Foundation.
76 ** All rights reserved.
77 **
78 ** This library is derived, with permission, from the International
79 ** Astronomical Union's "Standards of Fundamental Astronomy" library,
80 ** available from http://www.iausofa.org.
81 **
82 ** The ERFA version is intended to retain identical functionality to
83 ** the SOFA library, but made distinct through different function and
84 ** file names, as set out in the SOFA license conditions. The SOFA
85 ** original has a role as a reference standard for the IAU and IERS,
86 ** and consequently redistribution is permitted only in its unaltered
87 ** state. The ERFA version is not subject to this restriction and
88 ** therefore can be included in distributions which do not support the
89 ** concept of "read only" software.
90 **
91 ** Although the intent is to replicate the SOFA API (other than
92 ** replacement of prefix names) and results (with the exception of
93 ** bugs; any that are discovered will be fixed), SOFA is not
94 ** responsible for any errors found in this version of the library.
95 **
96 ** If you wish to acknowledge the SOFA heritage, please acknowledge
97 ** that you are using a library derived from SOFA, rather than SOFA
98 ** itself.
99 **
100 **
101 ** TERMS AND CONDITIONS
102 **
103 ** Redistribution and use in source and binary forms, with or without
104 ** modification, are permitted provided that the following conditions
105 ** are met:
106 **
107 ** 1 Redistributions of source code must retain the above copyright
108 ** notice, this list of conditions and the following disclaimer.
109 **
110 ** 2 Redistributions in binary form must reproduce the above copyright
111 ** notice, this list of conditions and the following disclaimer in
112 ** the documentation and/or other materials provided with the
113 ** distribution.
114 **
115 ** 3 Neither the name of the Standards Of Fundamental Astronomy Board,
116 ** the International Astronomical Union nor the names of its
117 ** contributors may be used to endorse or promote products derived
118 ** from this software without specific prior written permission.
119 **
120 ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
121 ** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
122 ** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
123 ** FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
124 ** COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
125 ** INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
126 ** BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
127 ** LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
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132 **
133 */
134